1. "forums.freebsd.org" is not part of FDP i.e. /doc (web, docs) + manages in the base.
2. Although it happend that the "forums.freebsd.org" is a subdomain of the FreeBSD.org, but you have to think of it as a different website. e.g. "ForumsFreeBSD[.]org"
3. This Forums like every single other Forums has a navigation menu/bar (New posts, CP, etc) and of course a "Home" item too.
4. Traditionally, both "Home" AND "Logo" will "href" to the 1st page.
5. BUT: FreeBSD Forums provides an additional menu -- copied from FreeBSD.org. Why? To help users finding their way through the docs, man, src, etc.
6. Thus, now we have two menus: the 1st one, which is the "forums.freebsd.org" menu (New posts, user profile, etc), and the others is an auxiliary menu to the "FreeBSD.org".
7. BUT! now we have two "Home" items. One for "forums.freebsd.org", and another one for the "FreeBSD.org".
What's the solution?
* Most people are not Forums member -- they visit the FreeBSD.org. So they expect, "Home" item send them to the 1st page of the "FreeBSD.org".
===> "Home" item --> FreeBSD.org
* Forums members need a way to reach, to the home page of the Forums.
===> "Logo" -------> forums.FreeBSD.org
And to me, the whole thing makes perfect sense.